The mother board is used to convert between different logic levels (5V TTL <-> 3.3V TTL), improve signal quality and provide interface to the motor driver board, the core board, the nRF2401A module, four encoders and a infrared sensor. (The board is designed using Altium Designer 17.1)
The 2D and 3D design views are shown below:
The main features are:
- Provide power supply (LM2576T-5.0 and TPS79401) for the core board and components on the mother board. (LiPo Battery (4S) 14.8-16.8V to 5V and 3.3V)
- Schmitt-trigger inverters (74LV14A, SN74HC14) complete the logic level convert and improve the signal quality.
- A/D (TLC0834) measures the battery and capacitor voltage.
- I/O expander (PCA9557PW) and rotary DIP switch (A6R/A6RV) for easier robot number, frequency and mode set.
- EEPROM (AT24C08) stores calibration data for each robot.
- Serial port (MAX232CSE) for communication with PC.
The photos of the mother board are shown below as references.
